What is the number of chromosomes in a human sperm cell?

In the given figure,the parts $A, B$,and $C$ are sequentially:

Which among the following statements are true for sexual reproduction in flowering plants?
$(i)$ It requires two types of gametes
$(ii)$ Fertilisation is a compulsory event
$(iii)$ It always results in formation of zygote
$(iv)$ Offspring formed are clones

$A$ simple multicellular animal that has tentacles and lives in freshwater. Which of the following asexual methods of reproduction does it use?

Which method of asexual reproduction occurs in $Amoeba$?

Define the following processes of asexual reproduction:
$(a)$ Spore formation
$(b)$ Regeneration
$(c)$ Multiple fission